This invention relates to digital contour generators and more particularly to apparatus for generating digitized data defining coordinates of the surface contours of complex-shaped three-dimensional objects.
Accepted procedures for mass producing three-dimensional objects generally involve the initial creation of a full-size or fractional-scale model thereof. Dies, patterns, or other tooling are then made that can reproduce the exact configurations of the curved surfaces and other complexities of the original model, plus other features such as attaching points, strengthening ribs, mating surfaces, etc.
Dimensional engineering drawings of such objects are extremely costly and do not provide the flexibility usually needed for making male and female dies, patterns to required shrink dimensions, and inspection tools and gages. In addition, it is so time consuming to go through such a transfer process that the drawing phase is bypassed if at all possible. Engineering or styling changes further complicate the problem. As a result, there are frequently no complete records or any way of documenting, expediting and coordinating the engineering in a systematic manner.
Numerical control machine tools can, with proper control in digital form, eliminate the necessity for most drawings. However, digitized X, Y and Z coordinate data from the model must first be obtained. Conventional apparatus for obtaining such data requires not only some direct contact with the model, but is slow operating and subject to mechanical restrictions.
Accordingly, one of the objects of the present invention is to provide non-contact apparatus for digitizing the X, Y and Z coordinates of three-dimensional objects having complex contoured surfaces.
Another object of the invention is to provide apparatus for automatically digitally generating, at high speed, coordinate data defining the outer surface of a three-dimensional model whose shape includes non-uniformly curved portions.
Still another object of the present invention is to provide apparatus for automatically generating the X, Y and Z coordinates of the surface of an irregularly shaped three-dimensional model for use in preparing a numerical control tape for making drawings, dies and tools as needed to produce the model.
Briefly, the digitizing apparatus in accordance with the present invention provides an adjustable illuminator means that is capable of illuminating a model to provide a contour line thereabout at selected levels or planes along its height which represents the Z coordinate axis. A camera disposed with its optical axis perpendicular to the plane of the illumination provides for projecting the contour line thus formed on the model onto the image or focal plane of the camera. The image plane of the camera represents the X and Y coordinate plane. Located within the camera so as to lie in the image plane thereof are photosensitive sensing means operable to digitally scan the image plane and thereby provide X and Y coordinates of the image of the contour line focussed thereon. These X and Y coordinates together with the Z coordinate of the plane of the contour line on the model provide digitized data which can be fed into an electronic computer and modified to prepare a numerical control tape useful for operating machine tools to duplicate the model.
Still further objects, advantages and features of the invention will become more fully apparent to one skilled in the pertinent art when the following specification and claims are read in the light of the accompanying drawings.